Forum Home > GMAT > Quantitative > Problem Solving (PS)
Events & Promotions
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Jul 2710:00 AM PDT
-11:00 AM PDT
Are you struggling with the GMAT verbal section? Do tricky questions and lengthy passages overwhelm you? Don't worry—I've got you covered! In this video, I'll provide a detailed, actionable plan to help you significantly boost your verbal score.
Jul 2508:00 AM EDT
-11:59 PM EDT
More and more TTP students are earning impressive scores on the GMAT. Now is the perfect time to join the many GMAT students who made the switch to TTP and surpassed their wildest expectations on test day.- Jul 28
10:00 AM PDT
-11:00 AM PDT
We will learn how to guess an answer choice better on the GMAT. If you are running out of time and want to guess on a few questions, these effective techniques will help you in making a smart guess. 
Jul 2811:00 AM IST
-01:00 PM IST
Attend this free GMAT Algebra Webinar and learn how to master the most challenging Inequalities and Absolute Value problems with ease.- Jul 31
05:55 AM PDT
-12:30 PM PDT
MBA Application Walkthrough and Essay Review. You will have a chance to hear from experts covering the Top 15 MBA programs, covering details of the application and essays. 
Jul 3110:00 AM EDT
-11:59 PM PDT
Save 20% on Target Test Prep and Score in the 100th Percentile in GMAT Verbal! Our course uses techniques such as topical study and spaced repetition to maximize knowledge retention and make studying simple and fun.
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 10133
Given Kudos: 4
GMAT 1: 760 Q51 V42
GPA: 3.82
John traveled the entire 50 km trip. If he travelled the first 20 km o
[#permalink]
02 Mar 2018, 01:21
02 Mar 2018, 01:21
1
Bookmarks
Expert Reply
Show timer
00:00
A
B
C
D
E
Difficulty:
5%
(low)
Question Stats:
92% (01:25) correct
8%
(02:12)
wrong
based on 199
sessions
[GMAT math practice question]
John traveled the entire 50 km trip. If he traveled the first 20 km of the trip at a constant rate 40 km per hour and the remaining trip at a constant rate 20 km per hour, what is his average speed, in km per hour?
A. 20 km/h
B. 23 km/h
C. 25 km/h
D. 26 km/h
E. 27 km/h
John traveled the entire 50 km trip. If he traveled the first 20 km of the trip at a constant rate 40 km per hour and the remaining trip at a constant rate 20 km per hour, what is his average speed, in km per hour?
A. 20 km/h
B. 23 km/h
C. 25 km/h
D. 26 km/h
E. 27 km/h
Re: John traveled the entire 50 km trip. If he travelled the first 20 km o
[#permalink]
02 Mar 2018, 02:00
02 Mar 2018, 02:00
MathRevolution wrote:
[GMAT math practice question]
John traveled the entire 50 km trip. If he traveled the first 20 km of the trip at a constant rate 40 km per hour and the remaining trip at a constant rate 20 km per hour, what is his average speed, in km per hour?
A. 20 km/h
B. 23 km/h
C. 25 km/h
D. 26 km/h
E. 27 km/h
John traveled the entire 50 km trip. If he traveled the first 20 km of the trip at a constant rate 40 km per hour and the remaining trip at a constant rate 20 km per hour, what is his average speed, in km per hour?
A. 20 km/h
B. 23 km/h
C. 25 km/h
D. 26 km/h
E. 27 km/h
If John travels 20 km at 40 km/hr he would take \(\frac{1}{2}\) hour.
The remainder of the trip - 30 km was traveled at 20 km/hr and took a time of \(\frac{30}{20} = \frac{3}{2}\) hours.
The total time taken is 2 hours and the distance traveled is 50 km.
Therefore, the average speed at which John travels is \(\frac{50}{2} = 25\)km/h (Option C)
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 6804
Given Kudos: 799
Location: Canada
Re: John traveled the entire 50 km trip. If he travelled the first 20 km o
[#permalink]
02 Mar 2018, 07:33
02 Mar 2018, 07:33
1
Kudos
Expert Reply
Top Contributor
MathRevolution wrote:
[GMAT math practice question]
John traveled the entire 50 km trip. If he traveled the first 20 km of the trip at a constant rate 40 km per hour and the remaining trip at a constant rate 20 km per hour, what is his average speed, in km per hour?
A. 20 km/h
B. 23 km/h
C. 25 km/h
D. 26 km/h
E. 27 km/h
John traveled the entire 50 km trip. If he traveled the first 20 km of the trip at a constant rate 40 km per hour and the remaining trip at a constant rate 20 km per hour, what is his average speed, in km per hour?
A. 20 km/h
B. 23 km/h
C. 25 km/h
D. 26 km/h
E. 27 km/h
Average speed = total distance/total travel time
total distance = 50 km
total travel time = time spent driving at 40 kmh + time spent driving at 20 kmh
time = distance/speed
So, time spent driving at 40 kmh = 20/40 = 1/2 hour
And time spent driving at 20 kmh = 30/20 = 3/2 hours
So, TOTAL travel time = 1/2 + 3/2 = 4/2 = 2 hours
Average speed = 50/2 = 25 kmh
Answer: C
RELATED VIDEO
